/**
 * Copyright (c) 2005-2013 by Appcelerator, Inc. All Rights Reserved.
 * Licensed under the terms of the Eclipse Public License (EPL).
 * Please see the license.txt included with this distribution for details.
 * Any modifications to this file must keep this entire header intact.
 */
package org.python.pydev.utils.tablecombo;

import java.lang.reflect.InvocationTargetException;

import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.accessibility.ACC;
import org.eclipse.swt.accessibility.AccessibleAdapter;
import org.eclipse.swt.accessibility.AccessibleControlAdapter;
import org.eclipse.swt.accessibility.AccessibleControlEvent;
import org.eclipse.swt.accessibility.AccessibleEvent;
import org.eclipse.swt.accessibility.AccessibleTextAdapter;
import org.eclipse.swt.accessibility.AccessibleTextEvent;
import org.eclipse.swt.events.KeyListener;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.events.VerifyListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Layout;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableColumn;
import org.eclipse.swt.widgets.TableItem;
import org.eclipse.swt.widgets.Text;
import org.eclipse.swt.widgets.TypedListener;
import org.eclipse.swt.widgets.Widget;

/**
 * From http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.swt.nebula/org.eclipse.nebula.widgets.tablecombo/src/org/eclipse/nebula/?root=Technology_Project
 * 
 * The TableCombo class represents a selectable user interface object
 * that combines a label, textfield, and a table and issues notification
 * when an item is selected from the table.
 * 
 * Note: This widget is basically a extension of the CCombo widget.  The list
 * control was replaced by a Table control and a Label control was added so that
 * images can be displayed when a value from the drop down items has a image 
 * associated to it.
 *  
 * <p>
 * TableCombo was written to allow the user to be able to display multiple
 * columns of data in the "Drop Down" portion of the combo.
 * </p>
 * <p>
 * Special Note: Although this class is a subclass of <code>Composite</code>,
 * it does not make sense to add children to it, or set a layout on it.
 * </p>
 * <dl>
 * <dt><b>Styles:</b>
 * <dd>BORDER, READ_ONLY, FLAT</dd>
 * <dt><b>Events:</b>
 * <dd>DefaultSelection, Modify, Selection, Verify</dd>
 * </dl>
 *
 */

public class TableCombo extends Composite {
    private Shell popup;
    private Button arrow;
    private Label selectedImage;
    private Text text;
    private Table table;
    private Font font;
    private boolean hasFocus;
    private int visibleItemCount = 7;
    private Listener listener;
    private Listener focusFilter;
    private int displayColumnIndex = 0;
    private Color foreground;
    private Color background;
    private int[] columnWidths;
    private int tableWidthPercentage = 100;
    private boolean showImageWithinSelection = true;
    private boolean showColorWithinSelection = true;
    private boolean showFontWithinSelection = true;

    /**
     * Constructs a new instance of this class given its parent
     * and a style value describing its behavior and appearance.
     * <p>
     * The style value is either one of the style constants defined in
     * class <code>SWT</code> which is applicable to instances of this
     * class, or must be built by <em>bitwise OR</em>'ing together 
     * (that is, using the <code>int</code> "|" operator) two or more
     * of those <code>SWT</code> style constants. The class description
     * lists the style constants that are applicable to the class.
     * Style bits are also inherited from superclasses.
     * </p>
     *
     * @param parent a widget which will be the parent of the new instance (cannot be null)
     * @param style the style of widget to construct
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
     * </ul>
     *
     * @see SWT#BORDER
     * @see SWT#READ_ONLY
     * @see SWT#FLAT
     * @see Widget#getStyle()
     */
    public TableCombo(Composite parent, int style) {
        super(parent, style = checkStyle(style));

        // set the label style
        int textStyle = SWT.SINGLE;
        if ((style & SWT.READ_ONLY) != 0)
            textStyle |= SWT.READ_ONLY;
        if ((style & SWT.FLAT) != 0)
            textStyle |= SWT.FLAT;

        // create label to hold image if necessary.
        selectedImage = new Label(this, SWT.NONE);
        selectedImage.setAlignment(SWT.RIGHT);
        selectedImage.setBackground(Display.getCurrent().getSystemColor(SWT.COLOR_WHITE));

        getLayout();

        // create the control to hold the display text of what the user selected.
        text = new Text(this, textStyle);
        text.setBackground(Display.getCurrent().getSystemColor(SWT.COLOR_WHITE));

        // set the arrow style.
        int arrowStyle = SWT.ARROW | SWT.DOWN;
        if ((style & SWT.FLAT) != 0)
            arrowStyle |= SWT.FLAT;

        // create the down arrow button
        arrow = new Button(this, arrowStyle);

        // now add a listener to listen to the events we are interested in.
        listener = new Listener() {
            @Override
            public void handleEvent(Event event) {
                if (isDisposed())
                    return;

                // check for a popup event
                if (popup == event.widget) {
                    popupEvent(event);
                    return;
                }

                if (text == event.widget) {
                    textEvent(event);
                    return;
                }

                // check for a table event
                if (table == event.widget) {
                    tableEvent(event);
                    return;
                }

                // check for arrow event
                if (arrow == event.widget) {
                    arrowEvent(event);
                    return;
                }

                // check for this widget's event
                if (TableCombo.this == event.widget) {
                    comboEvent(event);
                    return;
                }

                // check for shell event
                if (getShell() == event.widget) {
                    getDisplay().asyncExec(new Runnable() {
                        @Override
                        public void run() {
                            if (isDisposed())
                                return;
                            handleFocus(SWT.FocusOut);
                        }
                    });
                }
            }
        };

        // create new focus listener
        focusFilter = new Listener() {
            @Override
            public void handleEvent(Event event) {
                if (isDisposed())
                    return;
                Shell shell = ((Control) event.widget).getShell();

                if (shell == TableCombo.this.getShell()) {
                    handleFocus(SWT.FocusOut);
                }
            }
        };

        // set the listeners for this control
        int[] comboEvents = { SWT.Dispose, SWT.FocusIn, SWT.Move, SWT.Resize };
        for (int i = 0; i < comboEvents.length; i++)
            this.addListener(comboEvents[i], listener);

        int[] textEvents = { SWT.DefaultSelection, SWT.KeyDown, SWT.KeyUp, SWT.MenuDetect, SWT.Modify, SWT.MouseDown,
                SWT.MouseUp, SWT.MouseDoubleClick, SWT.MouseWheel, SWT.Traverse, SWT.FocusIn, SWT.Verify };
        for (int i = 0; i < textEvents.length; i++)
            text.addListener(textEvents[i], listener);

        // set the listeners for the arrow image
        int[] arrowEvents = { SWT.Selection, SWT.FocusIn };
        for (int i = 0; i < arrowEvents.length; i++)
            arrow.addListener(arrowEvents[i], listener);

        // initialize the drop down
        createPopup(-1);

        initAccessible();
    }

    /**
     * @param style
     * @return
     */
    private static int checkStyle(int style) {
        int mask = SWT.BORDER | SWT.READ_ONLY | SWT.FLAT | SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT;
        return SWT.NO_FOCUS | (style & mask);
    }

    /**
     * Adds the listener to the collection of listeners who will
     * be notified when the receiver's text is modified, by sending
     * it one of the messages defined in the <code>ModifyListener</code>
     * interface.
     *
     * @param listener the listener which should be notified
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     *
     * @see ModifyListener
     * @see #removeModifyListener
     */
    public void addModifyListener(ModifyListener listener) {
        checkWidget();
        if (listener == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        TypedListener typedListener = new TypedListener(listener);
        addListener(SWT.Modify, typedListener);
    }

    /**
     * Adds the listener to the collection of listeners who will
     * be notified when the user changes the receiver's selection, by sending
     * it one of the messages defined in the <code>SelectionListener</code>
     * interface.
     * <p>
     * <code>widgetSelected</code> is called when the combo's list selection changes.
     * <code>widgetDefaultSelected</code> is typically called when ENTER is pressed the combo's text area.
     * </p>
     *
     * @param listener the listener which should be notified when the user changes the receiver's selection
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     *
     * @see SelectionListener
     * @see #removeSelectionListener
     * @see SelectionEvent
     */
    public void addSelectionListener(SelectionListener listener) {
        checkWidget();
        if (listener == null) {
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        }

        TypedListener typedListener = new TypedListener(listener);
        addListener(SWT.Selection, typedListener);
        addListener(SWT.DefaultSelection, typedListener);
    }

    /**
     * Adds the listener to the collection of listeners who will
     * be notified when the user presses keys in the text field.
     * interface.
     *
     * @param listener the listener which should be notified when the user presses keys in the text control.
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public void addTextControlKeyListener(KeyListener listener) {
        checkWidget();
        if (listener == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        text.addKeyListener(listener);
    }

    /**
     * Removes the listener from the collection of listeners who will
     * be notified when the user presses keys in the text control.
     *
     * @param listener the listener which should no longer be notified
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     *
     */
    public void removeTextControlKeyListener(KeyListener listener) {
        checkWidget();
        if (listener == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        text.removeKeyListener(listener);
    }

    /**
     * Adds the listener to the collection of listeners who will
     * be notified when the receiver's text is verified, by sending
     * it one of the messages defined in the <code>VerifyListener</code>
     * interface.
     *
     * @param listener the listener which should be notified
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     *
     * @see VerifyListener
     * @see #removeVerifyListener
     * 
     * @since 3.3
     */
    public void addVerifyListener(VerifyListener listener) {
        checkWidget();
        if (listener == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        TypedListener typedListener = new TypedListener(listener);
        addListener(SWT.Verify, typedListener);
    }

    /**
     * Handle Arrow Event
     * @param event
     */
    private void arrowEvent(Event event) {
        switch (event.type) {
            case SWT.FocusIn: {
                handleFocus(SWT.FocusIn);
                break;
            }
            case SWT.MouseDown: {
                Event mouseEvent = new Event();
                mouseEvent.button = event.button;
                mouseEvent.count = event.count;
                mouseEvent.stateMask = event.stateMask;
                mouseEvent.time = event.time;
                mouseEvent.x = event.x;
                mouseEvent.y = event.y;
                notifyListeners(SWT.MouseDown, mouseEvent);
                event.doit = mouseEvent.doit;
                break;
            }
            case SWT.MouseUp: {
                Event mouseEvent = new Event();
                mouseEvent.button = event.button;
                mouseEvent.count = event.count;
                mouseEvent.stateMask = event.stateMask;
                mouseEvent.time = event.time;
                mouseEvent.x = event.x;
                mouseEvent.y = event.y;
                notifyListeners(SWT.MouseUp, mouseEvent);
                event.doit = mouseEvent.doit;
                break;
            }
            case SWT.Selection: {
                text.setFocus();
                dropDown(!isDropped());
                break;
            }
        }
    }

    /**
     * Sets the selection in the receiver's text field to an empty
     * selection starting just before the first character. If the
     * text field is editable, this has the effect of placing the
     * i-beam at the start of the text.
     * <p>
     * Note: To clear the selected items in the receiver's list, 
     * use <code>deselectAll()</code>.
     * </p>
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     *
     * @see #deselectAll
     */
    public void clearSelection() {
        checkWidget();
        text.clearSelection();
        table.deselectAll();
    }

    /**
     * Handle Combo events
     * @param event
     */
    private void comboEvent(Event event) {
        switch (event.type) {
            case SWT.Dispose:
                removeListener(SWT.Dispose, listener);
                notifyListeners(SWT.Dispose, event);
                event.type = SWT.None;

                if (popup != null && !popup.isDisposed()) {
                    table.removeListener(SWT.Dispose, listener);
                    popup.dispose();
                }
                Shell shell = getShell();
                shell.removeListener(SWT.Deactivate, listener);
                Display display = getDisplay();
                display.removeFilter(SWT.FocusIn, focusFilter);
                popup = null;
                text = null;
                table = null;
                arrow = null;
                selectedImage = null;
                break;
            case SWT.FocusIn:
                Control focusControl = getDisplay().getFocusControl();
                if (focusControl == arrow || focusControl == table)
                    return;
                if (isDropped()) {
                    table.setFocus();
                } else {
                    text.setFocus();
                }
                break;
            case SWT.Move:
                dropDown(false);
                break;
            case SWT.Resize:
                internalLayout(false);
                break;
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Point computeSize(int wHint, int hHint, boolean changed) {
        checkWidget();
        int overallWidth = 0;
        int height = 0;

        TableItem[] tableItems = table.getItems();

        GC gc = new GC(text);
        int spacer = gc.stringExtent(" ").x; //$NON-NLS-1$
        int textWidth = gc.stringExtent(text.getText()).x;
        int colIndex = getDisplayColumnIndex();

        // calculate the maximum text width.
        for (int i = 0; i < tableItems.length; i++) {
            textWidth = Math.max(gc.stringExtent(tableItems[i].getText(colIndex)).x, textWidth);
        }
        gc.dispose();
        Point textSize = text.computeSize(SWT.DEFAULT, SWT.DEFAULT, changed);
        Point arrowSize = arrow.computeSize(SWT.DEFAULT, SWT.DEFAULT, changed);
        Point tableSize = table.computeSize(SWT.DEFAULT, SWT.DEFAULT, changed);
        int borderWidth = getBorderWidth();

        height = Math.max(textSize.y, arrowSize.y);
        overallWidth = Math.max(textWidth + 2 * spacer + arrowSize.x + 2 * borderWidth, tableSize.x);
        if (wHint != SWT.DEFAULT)
            overallWidth = wHint;
        if (hHint != SWT.DEFAULT)
            height = hHint;

        return new Point(overallWidth + 2 * borderWidth, height + 2 * borderWidth);
    }

    /**
     * Copies the selected text.
     * <p>
     * The current selection is copied to the clipboard.
     * </p>
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     * 
     * @since 3.3
     */
    public void copy() {
        checkWidget();
        text.copy();
    }

    /**
     * creates the popup shell.
     * @param selectionIndex
     */
    void createPopup(int selectionIndex) {
        // create shell and table
        popup = new Shell(getShell(), SWT.NO_TRIM | SWT.ON_TOP);

        // create table
        table = new Table(popup, SWT.SINGLE | SWT.FULL_SELECTION);

        if (font != null)
            table.setFont(font);
        if (foreground != null)
            table.setForeground(foreground);
        if (background != null)
            table.setBackground(background);

        // Add popup listeners
        int[] popupEvents = { SWT.Close, SWT.Paint, SWT.Deactivate };
        for (int i = 0; i < popupEvents.length; i++) {
            popup.addListener(popupEvents[i], listener);
        }

        // add table listeners
        int[] tableEvents = { SWT.MouseUp, SWT.Selection, SWT.Traverse, SWT.KeyDown, SWT.KeyUp, SWT.FocusIn,
                SWT.Dispose };
        for (int i = 0; i < tableEvents.length; i++) {
            table.addListener(tableEvents[i], listener);
        }

        // set the selection
        if (selectionIndex != -1) {
            table.setSelection(selectionIndex);
        }
    }

    /**
     * Cuts the selected text.
     * <p>
     * The current selection is first copied to the
     * clipboard and then deleted from the widget.
     * </p>
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     * 
     * @since 3.3
     */
    public void cut() {
        checkWidget();
        text.cut();
    }

    /**
     * handle DropDown request
     * @param drop
     */
    void dropDown(boolean drop) {

        // if already dropped then return
        if (drop == isDropped())
            return;

        // closing the dropDown
        if (!drop) {
            popup.setVisible(false);
            if (!isDisposed() && isFocusControl()) {
                text.setFocus();
            }
            return;
        }

        // if not visible then return
        if (!isVisible())
            return;

        // create a new popup if needed.
        if (getShell() != popup.getParent()) {
            int selectionIndex = table.getSelectionIndex();
            table.removeListener(SWT.Dispose, listener);
            popup.dispose();
            popup = null;
            table = null;
            createPopup(selectionIndex);
        }

        // get the size of the TableCombo.
        Point tableComboSize = getSize();

        // calculate the table height.
        int itemCount = table.getItemCount();
        itemCount = (itemCount == 0) ? visibleItemCount : Math.min(visibleItemCount, itemCount) - 1;
        int itemHeight = (table.getItemHeight() * itemCount);

        // add 1 to the table height if the table item count is less than the visible item count.  
        if (table.getItemCount() <= visibleItemCount) {
            itemHeight += 1;
        }

        // add height of header if the header is being displayed.
        if (table.getHeaderVisible()) {
            itemHeight += table.getHeaderHeight();
        }

        // get table column references
        TableColumn[] tableColumns = table.getColumns();
        int totalColumns = (tableColumns == null ? 0 : tableColumns.length);

        // check to make sure at least one column has been specified.  if it hasn't
        // then just create a blank one.
        if (table.getColumnCount() == 0) {
            new TableColumn(table, SWT.NONE);
            totalColumns = 1;
            tableColumns = table.getColumns();
        }

        int totalColumnWidth = 0;
        // now pack any columns that do not have a explicit value set for them.
        for (int colIndex = 0; colIndex < totalColumns; colIndex++) {
            if (!wasColumnWidthSpecified(colIndex)) {
                tableColumns[colIndex].pack();
            }
            totalColumnWidth += tableColumns[colIndex].getWidth();
        }

        // calculate the table size after making adjustments.
        Point tableSize = table.computeSize(SWT.DEFAULT, itemHeight, false);

        // calculate the table width and table height.
        double pct = tableWidthPercentage / 100d;
        int tableWidth = (int) (Math.max(tableComboSize.x - 2, tableSize.x) * pct);
        int tableHeight = tableSize.y;

        // add the width of a horizontal scrollbar to the table height if we are
        // not viewing the full table.
        if (tableWidthPercentage < 100) {
            tableHeight += table.getHorizontalBar().getSize().y;
        }

        // set the bounds on the table.
        table.setBounds(1, 1, tableWidth, tableHeight);

        // adjust any of the columns to make sure that there is no empty space after
        // the last column.
        autoAdjustColumnWidthsIfNeeded(tableColumns, tableWidth, totalColumnWidth);

        // set the table top index if there is a valid selection.
        int index = table.getSelectionIndex();
        if (index != -1) {
            table.setTopIndex(index);
        }

        // calculate popup dimensions.
        Display display = getDisplay();
        Rectangle tableRect = table.getBounds();
        Rectangle parentRect = display.map(getParent(), null, getBounds());
        Point comboSize = getSize();
        Rectangle displayRect = getMonitor().getClientArea();

        int overallWidth = 0;

        // now set what the overall width should be.
        if (tableWidthPercentage < 100) {
            overallWidth = tableRect.width + 2;
        } else {
            overallWidth = Math.max(comboSize.x, tableRect.width + 2);
        }

        int overallHeight = tableRect.height + 2;
        int x = parentRect.x;
        int y = parentRect.y + comboSize.y;
        if (y + overallHeight > displayRect.y + displayRect.height)
            y = parentRect.y - overallHeight;
        if (x + overallWidth > displayRect.x + displayRect.width)
            x = displayRect.x + displayRect.width - tableRect.width;

        // set the bounds of the popup
        popup.setBounds(x, y, overallWidth, overallHeight);

        // set the popup visible
        popup.setVisible(true);

        // set focus on the table.
        table.setFocus();
    }

    /* 
     * Return the Label immediately preceding the receiver in the z-order, 
     * or null if none. 
     */
    private Label getAssociatedLabel() {
        Control[] siblings = getParent().getChildren();
        for (int i = 0; i < siblings.length; i++) {
            if (siblings[i] == TableCombo.this) {
                if (i > 0 && siblings[i - 1] instanceof Label) {
                    return (Label) siblings[i - 1];
                }
            }
        }
        return null;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Control[] getChildren() {
        checkWidget();
        return new Control[0];
    }

    /**
     * Gets the editable state.
     *
     * @return whether or not the receiver is editable
     * 
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     * 
     * @since 3.0
     */
    public boolean getEditable() {
        checkWidget();
        return text.getEditable();
    }

    /**
     * Returns the item at the given, zero-relative index in the
     * receiver's list. Throws an exception if the index is out
     * of range.
     *
     * @param index the index of the item to return
     * @return the item at the given index
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public String getItem(int index) {
        checkWidget();
        return table.getItem(index).getText(getDisplayColumnIndex());
    }

    /**
     * Returns the number of items contained in the receiver's list.
     *
     * @return the number of items
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public int getItemCount() {
        checkWidget();
        return table.getItemCount();
    }

    /**
     * Returns the height of the area which would be used to
     * display <em>one</em> of the items in the receiver's list.
     *
     * @return the height of one item
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public int getItemHeight() {
        checkWidget();
        return table.getItemHeight();
    }

    /**
     * Returns an array of <code>String</code>s which are the items
     * in the receiver's list. 
     * <p>
     * Note: This is not the actual structure used by the receiver
     * to maintain its list of items, so modifying the array will
     * not affect the receiver. 
     * </p>
     *
     * @return the items in the receiver's list
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public String[] getItems() {
        checkWidget();

        // get a list of the table items.
        TableItem[] tableItems = table.getItems();

        int totalItems = (tableItems == null ? 0 : tableItems.length);

        // create string array to hold the total number of items.
        String[] stringItems = new String[totalItems];

        int colIndex = getDisplayColumnIndex();

        // now copy the display string from the tableitems.
        for (int index = 0; index < totalItems; index++) {
            stringItems[index] = tableItems[index].getText(colIndex);
        }

        return stringItems;
    }

    /**
     * Returns a <code>Point</code> whose x coordinate is the start
     * of the selection in the receiver's text field, and whose y
     * coordinate is the end of the selection. The returned values
     * are zero-relative. An "empty" selection as indicated by
     * the the x and y coordinates having the same value.
     *
     * @return a point representing the selection start and end
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public Point getSelection() {
        checkWidget();
        return text.getSelection();
    }

    /**
     * Returns the zero-relative index of the item which is currently
     * selected in the receiver's list, or -1 if no item is selected.
     *
     * @return the index of the selected item
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public int getSelectionIndex() {
        checkWidget();
        return table.getSelectionIndex();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int getStyle() {
        checkWidget();

        int style = super.getStyle();
        style &= ~SWT.READ_ONLY;
        if (!text.getEditable())
            style |= SWT.READ_ONLY;
        return style;
    }

    /**
     * Returns a string containing a copy of the contents of the
     * receiver's text field.
     *
     * @return the receiver's text
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public String getText() {
        checkWidget();
        return text.getText();
    }

    /**
     * Returns the height of the receivers's text field.
     *
     * @return the text height
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public int getTextHeight() {
        checkWidget();
        return text.getLineHeight();
    }

    /**
     * Gets the number of items that are visible in the drop
     * down portion of the receiver's list.
     *
     * @return the number of items that are visible
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     * 
     * @since 3.0
     */
    public int getVisibleItemCount() {
        checkWidget();
        return visibleItemCount;
    }

    /**
     * Handle Focus event
     * @param type
     */
    private void handleFocus(int type) {
        switch (type) {
            case SWT.FocusIn: {
                if (hasFocus)
                    return;
                if (getEditable()) {
                    text.selectAll();
                }
                hasFocus = true;
                Shell shell = getShell();
                shell.removeListener(SWT.Deactivate, listener);
                shell.addListener(SWT.Deactivate, listener);
                Display display = getDisplay();
                display.removeFilter(SWT.FocusIn, focusFilter);
                display.addFilter(SWT.FocusIn, focusFilter);
                Event e = new Event();
                notifyListeners(SWT.FocusIn, e);
                break;
            }
            case SWT.FocusOut: {
                if (!hasFocus)
                    return;
                Control focusControl = getDisplay().getFocusControl();
                if (focusControl == arrow || focusControl == table || focusControl == text)
                    return;
                hasFocus = false;
                Shell shell = getShell();
                shell.removeListener(SWT.Deactivate, listener);
                Display display = getDisplay();
                display.removeFilter(SWT.FocusIn, focusFilter);
                Event e = new Event();
                notifyListeners(SWT.FocusOut, e);
                break;
            }
        }
    }

    /**
     * Searches the receiver's list starting at the first item
     * (index 0) until an item is found that is equal to the 
     * argument, and returns the index of that item. If no item
     * is found, returns -1.
     *
     * @param string the search item
     * @return the index of the item
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public int indexOf(String string) {
        checkWidget();
        if (string == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);

        // get a list of the table items.
        TableItem[] tableItems = table.getItems();

        int totalItems = (tableItems == null ? 0 : tableItems.length);
        int colIndex = getDisplayColumnIndex();

        // now copy the display string from the tableitems.
        for (int index = 0; index < totalItems; index++) {
            if (string.equals(tableItems[index].getText(colIndex))) {
                return index;
            }
        }

        return -1;
    }

    /**
     * Searches the receiver's list starting at the given, 
     * zero-relative index until an item is found that is equal
     * to the argument, and returns the index of that item. If
     * no item is found or the starting index is out of range,
     * returns -1.
     *
     * @param string the search item
     * @param start the zero-relative index at which to begin the search
     * @return the index of the item
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public int indexOf(String string, int start) {
        checkWidget();
        if (string == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);

        // get a list of the table items.
        TableItem[] tableItems = table.getItems();

        int totalItems = (tableItems == null ? 0 : tableItems.length);

        if (start < totalItems) {

            int colIndex = getDisplayColumnIndex();

            // now copy the display string from the tableitems.
            for (int index = start; index < totalItems; index++) {
                if (string.equals(tableItems[index].getText(colIndex))) {
                    return index;
                }
            }
        }

        return -1;
    }

    /**
     * sets whether or not to show table lines
     * @param showTableLines
     */
    public void setShowTableLines(boolean showTableLines) {
        checkWidget();
        table.setLinesVisible(showTableLines);
    }

    /**
     * sets whether or not to show table header.
     * @param showTableHeader
     */
    public void setShowTableHeader(boolean showTableHeader) {
        checkWidget();
        table.setHeaderVisible(showTableHeader);
    }

    /**
     * Add Accessbile listeners to label and table.
     */
    void initAccessible() {
        AccessibleAdapter accessibleAdapter = new AccessibleAdapter() {
            @Override
            public void getName(AccessibleEvent e) {
                String name = null;
                Label label = getAssociatedLabel();
                if (label != null) {
                    name = stripMnemonic(text.getText());
                }
                e.result = name;
            }

            @Override
            public void getKeyboardShortcut(AccessibleEvent e) {
                String shortcut = null;
                Label label = getAssociatedLabel();
                if (label != null) {
                    String text = label.getText();
                    if (text != null) {
                        char mnemonic = _findMnemonic(text);
                        if (mnemonic != '\0') {
                            shortcut = "Alt+" + mnemonic; //$NON-NLS-1$
                        }
                    }
                }
                e.result = shortcut;
            }

            @Override
            public void getHelp(AccessibleEvent e) {
                e.result = getToolTipText();
            }
        };

        getAccessible().addAccessibleListener(accessibleAdapter);
        text.getAccessible().addAccessibleListener(accessibleAdapter);
        table.getAccessible().addAccessibleListener(accessibleAdapter);

        arrow.getAccessible().addAccessibleListener(new AccessibleAdapter() {
            @Override
            public void getName(AccessibleEvent e) {
                e.result = isDropped() ? SWT.getMessage("SWT_Close") : SWT.getMessage("SWT_Open"); //$NON-NLS-1$ //$NON-NLS-2$
            }

            @Override
            public void getKeyboardShortcut(AccessibleEvent e) {
                e.result = "Alt+Down Arrow"; //$NON-NLS-1$
            }

            @Override
            public void getHelp(AccessibleEvent e) {
                e.result = getToolTipText();
            }
        });

        getAccessible().addAccessibleTextListener(new AccessibleTextAdapter() {
            @Override
            public void getCaretOffset(AccessibleTextEvent e) {
                e.offset = text.getCaretPosition();
            }

            @Override
            public void getSelectionRange(AccessibleTextEvent e) {
                Point sel = text.getSelection();
                e.offset = sel.x;
                e.length = sel.y - sel.x;
            }
        });

        getAccessible().addAccessibleControlListener(new AccessibleControlAdapter() {
            @Override
            public void getChildAtPoint(AccessibleControlEvent e) {
                Point testPoint = toControl(e.x, e.y);
                if (getBounds().contains(testPoint)) {
                    e.childID = ACC.CHILDID_SELF;
                }
            }

            @Override
            public void getLocation(AccessibleControlEvent e) {
                Rectangle location = getBounds();
                Point pt = getParent().toDisplay(location.x, location.y);
                e.x = pt.x;
                e.y = pt.y;
                e.width = location.width;
                e.height = location.height;
            }

            @Override
            public void getChildCount(AccessibleControlEvent e) {
                e.detail = 0;
            }

            @Override
            public void getRole(AccessibleControlEvent e) {
                e.detail = ACC.ROLE_COMBOBOX;
            }

            @Override
            public void getState(AccessibleControlEvent e) {
                e.detail = ACC.STATE_NORMAL;
            }

            @Override
            public void getValue(AccessibleControlEvent e) {
                e.result = text.getText();
            }
        });

        text.getAccessible().addAccessibleControlListener(new AccessibleControlAdapter() {
            @Override
            public void getRole(AccessibleControlEvent e) {
                e.detail = text.getEditable() ? ACC.ROLE_TEXT : ACC.ROLE_LABEL;
            }
        });

        arrow.getAccessible().addAccessibleControlListener(new AccessibleControlAdapter() {
            @Override
            public void getDefaultAction(AccessibleControlEvent e) {
                e.result = isDropped() ? SWT.getMessage("SWT_Close") : SWT.getMessage("SWT_Open"); //$NON-NLS-1$ //$NON-NLS-2$
            }
        });
    }

    /**
     * returns if the drop down is currently open
     * @return
     */
    private boolean isDropped() {
        return popup.getVisible();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean isFocusControl() {
        checkWidget();
        //if (label.isFocusControl () || arrow.isFocusControl () || table.isFocusControl () || popup.isFocusControl ()) {
        if (arrow.isFocusControl() || table.isFocusControl() || popup.isFocusControl()) {
            return true;
        }
        return super.isFocusControl();
    }

    /**
     * This method is invoked when a resize event occurs.
     * @param changed
     */
    private void internalLayout(boolean changed) {
        if (isDropped())
            dropDown(false);
        Rectangle rect = getClientArea();
        int width = rect.width;
        int height = rect.height;
        Point arrowSize = arrow.computeSize(SWT.DEFAULT, height, changed);

        if (selectedImage.getImage() == null) {
            selectedImage.setBounds(0, 0, 0, 0);
            text.setBounds(0, 0, width - arrowSize.x, height);
            arrow.setBounds(width - arrowSize.x, 0, arrowSize.x, arrowSize.y);
        } else {
            int imageWidth = selectedImage.computeSize(SWT.DEFAULT, height, changed).x + 2;
            int textWidth = width - imageWidth - arrowSize.x;

            selectedImage.setBounds(0, 0, imageWidth, height);
            text.setBounds(imageWidth, 0, textWidth, height);
            arrow.setBounds(imageWidth + textWidth, 0, arrowSize.x, arrowSize.y);
        }
    }

    /**
     * Handles Table Events.
     * @param event
     * @throws IllegalAccessException
     * @throws InvocationTargetException
     * @throws NoSuchMethodException
     */
    private void tableEvent(Event event) {
        switch (event.type) {
            case SWT.Dispose:
                if (getShell() != popup.getParent()) {
                    int selectionIndex = table.getSelectionIndex();
                    popup = null;
                    table = null;
                    createPopup(selectionIndex);
                }
                break;
            case SWT.FocusIn: {
                handleFocus(SWT.FocusIn);
                break;
            }
            case SWT.MouseUp: {
                if (event.button != 1)
                    return;
                dropDown(false);
                break;
            }
            case SWT.Selection: {
                int index = table.getSelectionIndex();
                if (index == -1)
                    return;

                // refresh the text.
                refreshText(index);

                // set the selection in the table.
                table.setSelection(index);

                Event e = new Event();
                e.time = event.time;
                e.stateMask = event.stateMask;
                e.doit = event.doit;
                notifyListeners(SWT.Selection, e);
                event.doit = e.doit;
                break;
            }
            case SWT.Traverse: {
                switch (event.detail) {
                    case SWT.TRAVERSE_RETURN:
                    case SWT.TRAVERSE_ESCAPE:
                    case SWT.TRAVERSE_ARROW_PREVIOUS:
                    case SWT.TRAVERSE_ARROW_NEXT:
                        event.doit = false;
                        break;
                    case SWT.TRAVERSE_TAB_NEXT:
                    case SWT.TRAVERSE_TAB_PREVIOUS:
                        event.doit = text.traverse(event.detail);
                        event.detail = SWT.TRAVERSE_NONE;
                        if (event.doit)
                            dropDown(false);
                        return;
                }
                Event e = new Event();
                e.time = event.time;
                e.detail = event.detail;
                e.doit = event.doit;
                e.character = event.character;
                e.keyCode = event.keyCode;
                notifyListeners(SWT.Traverse, e);
                event.doit = e.doit;
                event.detail = e.detail;
                break;
            }
            case SWT.KeyUp: {
                Event e = new Event();
                e.time = event.time;
                e.character = event.character;
                e.keyCode = event.keyCode;
                e.stateMask = event.stateMask;
                notifyListeners(SWT.KeyUp, e);
                break;
            }
            case SWT.KeyDown: {
                if (event.character == SWT.ESC) {
                    // Escape key cancels popup list
                    dropDown(false);
                }
                if ((event.stateMask & SWT.ALT) != 0
                        && (event.keyCode == SWT.ARROW_UP || event.keyCode == SWT.ARROW_DOWN)) {
                    dropDown(false);
                }
                if (event.character == SWT.CR || event.character == SWT.LF) {
                    // Enter causes default selection
                    dropDown(false);
                    Event e = new Event();
                    e.time = event.time;
                    e.stateMask = event.stateMask;
                    notifyListeners(SWT.DefaultSelection, e);
                }
                // At this point the widget may have been disposed.
                // If so, do not continue.
                if (isDisposed())
                    break;
                Event e = new Event();
                e.time = event.time;
                e.character = event.character;
                e.keyCode = event.keyCode;
                e.stateMask = event.stateMask;
                notifyListeners(SWT.KeyDown, e);
                break;

            }
        }
    }

    /**
     * Pastes text from clipboard.
     * <p>
     * The selected text is deleted from the widget
     * and new text inserted from the clipboard.
     * </p>
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     * 
     * @since 3.3
     */
    public void paste() {
        checkWidget();
        text.paste();
    }

    /**
     * Handles Popup Events
     * @param event
     */
    private void popupEvent(Event event) {
        switch (event.type) {
            case SWT.Paint:
                // draw rectangle around table
                Rectangle tableRect = table.getBounds();
                event.gc.setForeground(getDisplay().getSystemColor(SWT.COLOR_LIST_SELECTION));
                event.gc.drawRectangle(0, 0, tableRect.width + 1, tableRect.height + 1);
                break;
            case SWT.Close:
                event.doit = false;
                dropDown(false);
                break;
            case SWT.Deactivate:
                /*
                 * Bug in GTK. When the arrow button is pressed the popup control receives a
                 * deactivate event and then the arrow button receives a selection event. If 
                 * we hide the popup in the deactivate event, the selection event will show 
                 * it again. To prevent the popup from showing again, we will let the selection 
                 * event of the arrow button hide the popup.
                 * In Windows, hiding the popup during the deactivate causes the deactivate 
                 * to be called twice and the selection event to be disappear.
                 */
                if (!"carbon".equals(SWT.getPlatform())) {
                    Point point = arrow.toControl(getDisplay().getCursorLocation());
                    Point size = arrow.getSize();
                    Rectangle rect = new Rectangle(0, 0, size.x, size.y);
                    if (!rect.contains(point))
                        dropDown(false);
                } else {
                    dropDown(false);
                }
                break;
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void redraw() {
        super.redraw();
        text.redraw();
        arrow.redraw();
        if (popup.isVisible())
            table.redraw();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void redraw(int x, int y, int width, int height, boolean all) {
        super.redraw(x, y, width, height, true);
    }

    /**
     * Removes the listener from the collection of listeners who will
     * be notified when the receiver's text is modified.
     *
     * @param listener the listener which should no longer be notified
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     *
     * @see ModifyListener
     * @see #addModifyListener
     */
    public void removeModifyListener(ModifyListener listener) {
        checkWidget();
        if (listener == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        removeListener(SWT.Modify, listener);
    }

    /**
     * Removes the listener from the collection of listeners who will
     * be notified when the user changes the receiver's selection.
     *
     * @param listener the listener which should no longer be notified
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     *
     * @see SelectionListener
     * @see #addSelectionListener
     */
    public void removeSelectionListener(SelectionListener listener) {
        checkWidget();
        if (listener == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        removeListener(SWT.Selection, listener);
        removeListener(SWT.DefaultSelection, listener);
    }

    /**
     * Removes the listener from the collection of listeners who will
     * be notified when the control is verified.
     *
     * @param listener the listener which should no longer be notified
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     *
     * @see VerifyListener
     * @see #addVerifyListener
     * 
     * @since 3.3
     */
    public void removeVerifyListener(VerifyListener listener) {
        checkWidget();
        if (listener == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        removeListener(SWT.Verify, listener);
    }

    /**
     * Selects the item at the given zero-relative index in the receiver's 
     * list.  If the item at the index was already selected, it remains
     * selected. Indices that are out of range are ignored.
     *
     * @param index the index of the item to select
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public void select(int index) {
        checkWidget();

        // deselect if a value of -1 is passed in.
        if (index == -1) {
            table.deselectAll();
            text.setText("");
            selectedImage.setImage(null);
            return;
        }

        if (0 <= index && index < table.getItemCount()) {
            if (index != getSelectionIndex()) {

                // refresh the text field and image label
                refreshText(index);

                // select the row in the table.
                table.select(index);
                table.showSelection();
            }
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void setBackground(Color color) {
        super.setBackground(color);
        background = color;
        if (text != null)
            text.setBackground(color);
        if (selectedImage != null)
            selectedImage.setBackground(color);
        if (table != null)
            table.setBackground(color);
        if (arrow != null)
            arrow.setBackground(color);
    }

    /**
     * Sets the editable state.
     *
     * @param editable the new editable state
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     * 
     * @since 3.0
     */
    public void setEditable(boolean editable) {
        checkWidget();
        text.setEditable(editable);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void setEnabled(boolean enabled) {
        super.setEnabled(enabled);
        if (popup != null)
            popup.setVisible(false);
        if (selectedImage != null)
            selectedImage.setEnabled(enabled);
        if (text != null)
            text.setEnabled(enabled);
        if (arrow != null)
            arrow.setEnabled(enabled);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean setFocus() {
        checkWidget();
        if (!isEnabled() || !isVisible())
            return false;
        if (isFocusControl())
            return true;

        return text.setFocus();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void setFont(Font font) {
        super.setFont(font);
        this.font = font;
        text.setFont(font);
        table.setFont(font);
        internalLayout(true);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void setForeground(Color color) {
        super.setForeground(color);
        foreground = color;
        if (text != null)
            text.setForeground(color);
        if (table != null)
            table.setForeground(color);
        if (arrow != null)
            arrow.setForeground(color);
    }

    /**
     * Sets the layout which is associated with the receiver to be
     * the argument which may be null.
     * <p>
     * Note : No Layout can be set on this Control because it already
     * manages the size and position of its children.
     * </p>
     *
     * @param layout the receiver's new layout or null
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    @Override
    public void setLayout(Layout layout) {
        checkWidget();
        return;
    }

    /**
     * Marks the receiver's list as visible if the argument is <code>true</code>,
     * and marks it invisible otherwise.
     * <p>
     * If one of the receiver's ancestors is not visible or some
     * other condition makes the receiver not visible, marking
     * it visible may not actually cause it to be displayed.
     * </p>
     *
     * @param visible the new visibility state
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     * 
     * @since 3.4
     */
    public void setTableVisible(boolean visible) {
        checkWidget();
        dropDown(visible);
    }

    /**
     * Sets the selection in the receiver's text field to the
     * range specified by the argument whose x coordinate is the
     * start of the selection and whose y coordinate is the end
     * of the selection. 
     *
     * @param selection a point representing the new selection start and end
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the point is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public void setSelection(Point selection) {
        checkWidget();
        if (selection == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        text.setSelection(selection.x, selection.y);
    }

    /**
     * Sets the contents of the receiver's text field to the
     * given string.
     * <p>
     * Note: The text field in a <code>Combo</code> is typically
     * only capable of displaying a single line of text. Thus,
     * setting the text to a string containing line breaks or
     * other special characters will probably cause it to 
     * display incorrectly.
     * </p>
     *
     * @param string the new text
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public void setText(String string) {
        checkWidget();
        if (string == null) {
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        }

        // find the index of the given string.
        int index = indexOf(string);

        if (index == -1) {
            table.deselectAll();
            text.setText(string);
            return;
        }

        // select the text and table row.
        select(index);
    }

    /**
     * Sets the maximum number of characters that the receiver's
     * text field is capable of holding to be the argument.
     *
     * @param limit new text limit
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_CANNOT_BE_ZERO - if the limit is zero</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public void setTextLimit(int limit) {
        checkWidget();
        text.setTextLimit(limit);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void setToolTipText(String tipText) {
        checkWidget();
        super.setToolTipText(tipText);
        if (selectedImage != null)
            selectedImage.setToolTipText(tipText);
        if (text != null)
            text.setToolTipText(tipText);
        if (arrow != null)
            arrow.setToolTipText(tipText);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void setVisible(boolean visible) {
        super.setVisible(visible);
        /* 
         * At this point the widget may have been disposed in a FocusOut event.
         * If so then do not continue.
         */
        if (isDisposed())
            return;
        // TEMPORARY CODE
        if (popup == null || popup.isDisposed())
            return;
        if (!visible)
            popup.setVisible(false);
    }

    /**
     * Sets the number of items that are visible in the drop
     * down portion of the receiver's list.
     *
     * @param count the new number of items to be visible
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     * 
     * @since 3.0
     */
    public void setVisibleItemCount(int count) {
        checkWidget();
        if (count > 0) {
            visibleItemCount = count;
        }
    }

    /**
     * @param string
     * @return
     */
    private String stripMnemonic(String string) {
        int index = 0;
        int length = string.length();
        do {
            while ((index < length) && (string.charAt(index) != '&'))
                index++;
            if (++index >= length)
                return string;
            if (string.charAt(index) != '&') {
                return string.substring(0, index - 1) + string.substring(index, length);
            }
            index++;
        } while (index < length);
        return string;
    }

    /**
     * Defines what columns the drop down table will have.  
     * 
     * Use this method when you don't care about the width of the columns but
     * want to set the column header text.
     * @param columnHeaders
     * @param columnWidths
     */
    public void defineColumns(String[] columnHeaders) {
        if (columnHeaders != null && columnHeaders.length > 0) {
            defineColumnsInternal(columnHeaders, null, columnHeaders.length);
        }
    }

    /**
     * Defines what columns the drop down table will have.  
     * 
     * Use this method when you don't care about the column
     * header text but you want the fields to be a specific
     * width.
     * @param columnHeaders
     * @param columnBounds
     */
    public void defineColumns(int[] columnBounds) {
        this.columnWidths = columnBounds;

        if (columnBounds != null && columnBounds.length > 0) {
            defineColumnsInternal(null, columnBounds, columnBounds.length);
        }
    }

    /**
     * Defines what columns the drop down table will have.  
     * 
     * Use this method when you don't care about the column headers and
     * you want the columns to be automatically sized based upon their content.
     * 
     * @param columnHeaders
     * @param columnWidths
     */

    public void defineColumns(int numberOfColumnsToCreate) {
        if (numberOfColumnsToCreate > 0) {
            defineColumnsInternal(null, null, numberOfColumnsToCreate);
        }

    }

    /**
     * Defines what columns the drop down table will have.  
     * 
     * Use this method when you want to specify the column header text and the
     * column widths.
     * 
     * @param columnHeaders
     * @param columnBounds
     */
    public void defineColumns(String[] columnHeaders, int[] columnBounds) {
        if (columnHeaders != null || columnBounds != null) {
            int total = columnHeaders == null ? 0 : columnHeaders.length;
            if (columnBounds != null && columnBounds.length > total) {
                total = columnBounds.length;
            }

            this.columnWidths = columnBounds;

            // define the columns
            defineColumnsInternal(columnHeaders, columnBounds, total);
        }
    }

    /**
     * Defines what columns the drop down table will have.  
     * 
     * @param columnHeaders
     * @param columnBounds
     */
    private void defineColumnsInternal(String[] columnHeaders, int[] columnBounds, int totalColumnsToBeCreated) {

        checkWidget();

        int totalColumnHeaders = columnHeaders == null ? 0 : columnHeaders.length;
        int totalColBounds = columnBounds == null ? 0 : columnBounds.length;

        if (totalColumnsToBeCreated > 0) {

            for (int index = 0; index < totalColumnsToBeCreated; index++) {
                TableColumn column = new TableColumn(table, SWT.NONE);

                if (index < totalColumnHeaders) {
                    column.setText(columnHeaders[index]);
                }

                if (index < totalColBounds) {
                    column.setWidth(columnBounds[index]);
                }

                column.setResizable(true);
                column.setMoveable(true);
            }
        }
    }

    /**
     * Sets the table width percentage in relation to the width of the label control.
     * 
     * The default value if 100% which means that it will be the same size as the label
     * control.  If you want the table to be wider than the label then just display a value
     * higher than 100%.
     * @param ddWidthPct
     */
    public void setTableWidthPercentage(int ddWidthPct) {
        checkWidget();

        // don't accept invalid input.
        if (ddWidthPct > 0 && ddWidthPct <= 100) {
            this.tableWidthPercentage = ddWidthPct;
        }
    }

    /**
     * Sets the zero-relative column index that will be used to display
     * the currently selected item in the label control.
     * 
     * @param displayColumnIndex
     */
    public void setDisplayColumnIndex(int displayColumnIndex) {
        checkWidget();

        if (displayColumnIndex >= 0) {
            this.displayColumnIndex = displayColumnIndex;
        }
    }

    /**
     * returns the column index of the TableColumn to be displayed when selected.
     * @return
     */
    private int getDisplayColumnIndex() {
        // make sure the requested column index is valid.
        return (displayColumnIndex <= (table.getColumnCount() - 1) ? displayColumnIndex : 0);
    }

    /*
     * Return the lowercase of the first non-'&' character following
     * an '&' character in the given string. If there are no '&'
     * characters in the given string, return '\0'.
     */
    private char _findMnemonic(String string) {
        if (string == null)
            return '\0';
        int index = 0;
        int length = string.length();
        do {
            while (index < length && string.charAt(index) != '&')
                index++;
            if (++index >= length)
                return '\0';
            if (string.charAt(index) != '&')
                return Character.toLowerCase(string.charAt(index));
            index++;
        } while (index < length);
        return '\0';
    }

    /**
     * Refreshes the label control with the selected object's details.
     */
    private void refreshText(int index) {

        // get a reference to the selected TableItem
        TableItem tableItem = table.getItem(index);

        // get the TableItem index to use for displaying the text.
        int colIndexToUse = getDisplayColumnIndex();

        // set image if requested
        if (showImageWithinSelection) {
            // set the selected image
            selectedImage.setImage(tableItem.getImage(colIndexToUse));

            // refresh the layout of the widget
            internalLayout(false);
        }

        // set color if requested
        if (showColorWithinSelection) {
            text.setForeground(tableItem.getForeground(colIndexToUse));
        }

        // set font if requested
        if (showFontWithinSelection) {
            // set the selected font
            text.setFont(tableItem.getFont(colIndexToUse));
        }

        // set the label text.
        text.setText(tableItem.getText(colIndexToUse));
        text.selectAll();
    }

    /**
     * @param showImageWithinSelection
     */
    public void setShowImageWithinSelection(boolean showImageWithinSelection) {
        checkWidget();
        this.showImageWithinSelection = showImageWithinSelection;
    }

    /**
     * @param showColorWithinSelection
     */
    public void setShowColorWithinSelection(boolean showColorWithinSelection) {
        checkWidget();
        this.showColorWithinSelection = showColorWithinSelection;
    }

    /**
     * @param showFontWithinSelection
     */
    public void setShowFontWithinSelection(boolean showFontWithinSelection) {
        checkWidget();
        this.showFontWithinSelection = showFontWithinSelection;
    }

    /**
     * returns the Table reference.
     * 
     * NOTE: the access is public for now but will most likely be changed in a
     * future release.
     * 
     * @return
     */
    public Table getTable() {
        checkWidget();
        return table;
    }

    /**
     * determines if the user explicitly set a column width for a given column index.
     * @param columnIndex
     * @return
     */
    private boolean wasColumnWidthSpecified(int columnIndex) {
        return (columnWidths != null && columnWidths.length > columnIndex && columnWidths[columnIndex] != SWT.DEFAULT);
    }

    void textEvent(Event event) {
        switch (event.type) {
            case SWT.FocusIn: {
                handleFocus(SWT.FocusIn);
                break;
            }
            case SWT.DefaultSelection: {
                dropDown(false);
                Event e = new Event();
                e.time = event.time;
                e.stateMask = event.stateMask;
                notifyListeners(SWT.DefaultSelection, e);
                break;
            }
            case SWT.KeyDown: {
                Event keyEvent = new Event();
                keyEvent.time = event.time;
                keyEvent.character = event.character;
                keyEvent.keyCode = event.keyCode;
                keyEvent.stateMask = event.stateMask;
                notifyListeners(SWT.KeyDown, keyEvent);
                if (isDisposed())
                    break;
                event.doit = keyEvent.doit;
                if (!event.doit)
                    break;
                if (event.keyCode == SWT.ARROW_UP || event.keyCode == SWT.ARROW_DOWN) {
                    event.doit = false;
                    if ((event.stateMask & SWT.ALT) != 0) {
                        boolean dropped = isDropped();
                        text.selectAll();
                        if (!dropped)
                            setFocus();
                        dropDown(!dropped);
                        break;
                    }

                    int oldIndex = table.getSelectionIndex();
                    if (event.keyCode == SWT.ARROW_UP) {
                        select(Math.max(oldIndex - 1, 0));
                    } else {
                        select(Math.min(oldIndex + 1, getItemCount() - 1));
                    }
                    if (oldIndex != table.getSelectionIndex()) {
                        Event e = new Event();
                        e.time = event.time;
                        e.stateMask = event.stateMask;
                        notifyListeners(SWT.Selection, e);
                    }
                    if (isDisposed())
                        break;
                }

                // Further work : Need to add support for incremental search in 
                // pop up list as characters typed in text widget
                break;
            }
            case SWT.KeyUp: {
                Event e = new Event();
                e.time = event.time;
                e.character = event.character;
                e.keyCode = event.keyCode;
                e.stateMask = event.stateMask;
                notifyListeners(SWT.KeyUp, e);
                event.doit = e.doit;
                break;
            }
            case SWT.MenuDetect: {
                Event e = new Event();
                e.time = event.time;
                notifyListeners(SWT.MenuDetect, e);
                break;
            }
            case SWT.Modify: {
                table.deselectAll();
                Event e = new Event();
                e.time = event.time;
                notifyListeners(SWT.Modify, e);
                break;
            }
            case SWT.MouseDown: {
                Event mouseEvent = new Event();
                mouseEvent.button = event.button;
                mouseEvent.count = event.count;
                mouseEvent.stateMask = event.stateMask;
                mouseEvent.time = event.time;
                mouseEvent.x = event.x;
                mouseEvent.y = event.y;
                notifyListeners(SWT.MouseDown, mouseEvent);
                if (isDisposed())
                    break;
                event.doit = mouseEvent.doit;
                if (!event.doit)
                    break;
                if (event.button != 1)
                    return;
                if (text.getEditable())
                    return;
                boolean dropped = isDropped();
                text.selectAll();
                if (!dropped)
                    setFocus();
                dropDown(!dropped);
                break;
            }
            case SWT.MouseUp: {
                Event mouseEvent = new Event();
                mouseEvent.button = event.button;
                mouseEvent.count = event.count;
                mouseEvent.stateMask = event.stateMask;
                mouseEvent.time = event.time;
                mouseEvent.x = event.x;
                mouseEvent.y = event.y;
                notifyListeners(SWT.MouseUp, mouseEvent);
                if (isDisposed())
                    break;
                event.doit = mouseEvent.doit;
                if (!event.doit)
                    break;
                if (event.button != 1)
                    return;
                if (text.getEditable())
                    return;
                text.selectAll();
                break;
            }
            case SWT.MouseDoubleClick: {
                Event mouseEvent = new Event();
                mouseEvent.button = event.button;
                mouseEvent.count = event.count;
                mouseEvent.stateMask = event.stateMask;
                mouseEvent.time = event.time;
                mouseEvent.x = event.x;
                mouseEvent.y = event.y;
                notifyListeners(SWT.MouseDoubleClick, mouseEvent);
                break;
            }
            case SWT.MouseWheel: {
                Event keyEvent = new Event();
                keyEvent.time = event.time;
                keyEvent.keyCode = event.count > 0 ? SWT.ARROW_UP : SWT.ARROW_DOWN;
                keyEvent.stateMask = event.stateMask;
                notifyListeners(SWT.KeyDown, keyEvent);
                if (isDisposed())
                    break;
                event.doit = keyEvent.doit;
                if (!event.doit)
                    break;
                if (event.count != 0) {
                    event.doit = false;
                    int oldIndex = table.getSelectionIndex();
                    if (event.count > 0) {
                        select(Math.max(oldIndex - 1, 0));
                    } else {
                        select(Math.min(oldIndex + 1, getItemCount() - 1));
                    }
                    if (oldIndex != table.getSelectionIndex()) {
                        Event e = new Event();
                        e.time = event.time;
                        e.stateMask = event.stateMask;
                        notifyListeners(SWT.Selection, e);
                    }
                    if (isDisposed())
                        break;
                }
                break;
            }
            case SWT.Traverse: {
                switch (event.detail) {
                    case SWT.TRAVERSE_ARROW_PREVIOUS:
                    case SWT.TRAVERSE_ARROW_NEXT:
                        // The enter causes default selection and
                        // the arrow keys are used to manipulate the list contents so
                        // do not use them for traversal.
                        event.doit = false;
                        break;
                    case SWT.TRAVERSE_TAB_PREVIOUS:
                        event.doit = traverse(SWT.TRAVERSE_TAB_PREVIOUS);
                        event.detail = SWT.TRAVERSE_NONE;
                        return;
                }
                Event e = new Event();
                e.time = event.time;
                e.detail = event.detail;
                e.doit = event.doit;
                e.character = event.character;
                e.keyCode = event.keyCode;
                notifyListeners(SWT.Traverse, e);
                event.doit = e.doit;
                event.detail = e.detail;
                break;
            }
            case SWT.Verify: {
                Event e = new Event();
                e.text = event.text;
                e.start = event.start;
                e.end = event.end;
                e.character = event.character;
                e.keyCode = event.keyCode;
                e.stateMask = event.stateMask;
                notifyListeners(SWT.Verify, e);
                event.doit = e.doit;
                break;
            }
        }
    }

    /**
     * adjusts the table column widths to fit inside of the table if the table
     * column data does not fill out the table area.
     */
    private void autoAdjustColumnWidthsIfNeeded(TableColumn[] tableColumns, int totalAvailWidth,
            int totalColumnWidthUsage) {

        int totalColumns = (tableColumns == null ? 0 : tableColumns.length);

        int scrollBarSize = 0;

        // determine if the vertical scroll bar needs to be taken into account
        if (table.getItemCount() > visibleItemCount) {
            scrollBarSize = (table.getVerticalBar() == null ? 0 : table.getVerticalBar().getSize().x);
        }

        // is there any extra space that the table is not using?
        if (totalAvailWidth > totalColumnWidthUsage + scrollBarSize) {

            int totalAmtToBeAllocated = (totalAvailWidth - totalColumnWidthUsage - scrollBarSize);

            int totalBufferAmount = (int) Math.floor(totalAmtToBeAllocated / totalColumns);

            // add the buffer amount to each column 
            for (int colIndex = 0; colIndex < totalColumns; colIndex++) {
                tableColumns[colIndex].setWidth(tableColumns[colIndex].getWidth() + totalBufferAmount);
                totalAmtToBeAllocated -= totalBufferAmount;
            }

            // allocate any remainder to the last column.
            if (totalAmtToBeAllocated > 0) {
                tableColumns[totalColumns - 1].setWidth(tableColumns[totalColumns - 1].getWidth()
                        + totalAmtToBeAllocated);
            }
        }
    }

    /**
     * Returns the Text control reference.
     * @return
     */
    public Text getTextControl() {
        checkWidget();
        return text;
    }
}
